diff --git a/DSView/pv/config/appconfig.cpp b/DSView/pv/config/appconfig.cpp
index ac5d1c28..44c62989 100644
--- a/DSView/pv/config/appconfig.cpp
+++ b/DSView/pv/config/appconfig.cpp
@@ -72,7 +72,7 @@ void StringToFormatArray(const QString &str, vector<StringPair> &protocolFormats
 
 AppConfig::AppConfig()
 {
-    
+    _appOptions.quickScroll = true;
 }
 
 AppConfig::~AppConfig()
@@ -135,6 +135,12 @@ bool AppConfig::Save()
       QString  profomats = FormatArrayToString(m_protocolFormats);
       jobj["ProtocolFormats"] = QJsonValue::fromVariant(profomats);
 
+      //application options
+      QJsonObject app; 
+      app["QuickScroll"] = QJsonValue::fromVariant(_appOptions.quickScroll);
+  
+      jobj["Application"] = QJsonValue::fromVariant(app);
+
       QJsonDocument jdoc(jobj);
       QByteArray bytes = jdoc.toJson();
       string json;
@@ -155,6 +161,12 @@ bool AppConfig::Save()
           m_protocolFormats.clear();
           StringToFormatArray(jobj["ProtocolFormats"].toString(), m_protocolFormats);
       } 
+
+      //application node
+      if (jobj.contains("Application")){
+          QJsonObject app = jobj["Application"].toObject();
+          _appOptions.quickScroll = app["QuickScroll"].toBool();
+      } 
   }
 
 void AppConfig::SetProtocolFormat(const string &protocolName, const string &value)
diff --git a/DSView/pv/config/appconfig.h b/DSView/pv/config/appconfig.h
index ec2b2ee1..a5c93aea 100644
--- a/DSView/pv/config/appconfig.h
+++ b/DSView/pv/config/appconfig.h
@@ -26,13 +26,7 @@
 #include <vector>
 
 using namespace std;
-
-struct app_status{
-
-
-};
-
-
+  
 class StringPair
 {
 public:
@@ -41,13 +35,12 @@ public:
    string m_value;
 };
 
-class config_data
-{
-  public:
-
-    
+struct AppOptions
+{  
+    bool  quickScroll;    
 };
 
+  
 class AppConfig
 {
 private:
@@ -63,11 +56,10 @@ public:
   void FromJson(string &json);
 
   void SetProtocolFormat(const string &protocolName, const string &value);
-  string GetProtocolFormat(const string &protocolName);  
+  string GetProtocolFormat(const string &protocolName); 
 
 public:
-  config_data m_data;
-  app_status  m_status;
+  AppOptions _appOptions;
 
 private:
   string m_fileName;
diff --git a/DSView/pv/dialogs/applicationpardlg.cpp b/DSView/pv/dialogs/applicationpardlg.cpp
index 26e07484..b27da3a5 100644
--- a/DSView/pv/dialogs/applicationpardlg.cpp
+++ b/DSView/pv/dialogs/applicationpardlg.cpp
@@ -21,6 +21,10 @@
 
 #include "applicationpardlg.h"
 #include "dsdialog.h"
+#include <QFormLayout>
+#include <QCheckBox>
+#include <QString>
+#include "../config/appconfig.h"
 
 namespace pv
 {
@@ -29,7 +33,7 @@ namespace dialogs
 
 ApplicationParamDlg::ApplicationParamDlg()
 {
-    m_ret = false;
+   
 }
 
 ApplicationParamDlg::~ApplicationParamDlg()
@@ -39,14 +43,32 @@ ApplicationParamDlg::~ApplicationParamDlg()
 bool ApplicationParamDlg::ShowDlg(QWidget *parent)
 {
     DSDialog dlg(parent, true, true);
-    dlg.exec();
-    return m_ret;
-}
+    dlg.setMinimumSize(300, 200);
+    QFormLayout &lay = *(new QFormLayout());
+    lay.setContentsMargins(0,20,0,30);
 
-//------------IDlgCallback
-void ApplicationParamDlg::OnDlgResult(bool bYes){
-    m_ret = bYes;
- }
+    //show config
+    AppOptions &_app = AppConfig::Instance()._appOptions;
+
+    QCheckBox *ck_quickScroll = new QCheckBox();
+    ck_quickScroll->setChecked(_app.quickScroll);
+    lay.addRow("Quick scroll", ck_quickScroll);
+    dlg.layout()->addLayout(&lay);  
+     
+    dlg.exec();
+
+    bool ret = dlg.IsClickYes();
+
+    //save config
+    if (ret){
+        _app.quickScroll = ck_quickScroll->isChecked();
+
+        AppConfig::Instance().Save();
+    }
+   
+   return ret;
+}
+ 
 
 } //
 }//
diff --git a/DSView/pv/dialogs/applicationpardlg.h b/DSView/pv/dialogs/applicationpardlg.h
index 71e35d51..e890c985 100644
--- a/DSView/pv/dialogs/applicationpardlg.h
+++ b/DSView/pv/dialogs/applicationpardlg.h
@@ -23,14 +23,13 @@
 
 #include <QObject>
 #include <QWidget> 
-#include "../interface/uicallback.h"
 
 namespace pv
 {
  namespace dialogs
 {
 
-    class ApplicationParamDlg : private IDlgCallback
+    class ApplicationParamDlg 
     {
        // Q_OBJECT
 
@@ -44,8 +43,7 @@ namespace pv
     private:
         void OnDlgResult(bool bYes);
 
-    private:
-        bool  m_ret; 
+ 
     };
 
 }//
diff --git a/DSView/pv/dialogs/calibration.cpp b/DSView/pv/dialogs/calibration.cpp
index 36298622..e91d1722 100755
--- a/DSView/pv/dialogs/calibration.cpp
+++ b/DSView/pv/dialogs/calibration.cpp
@@ -31,6 +31,7 @@
 
 #include "../view/trace.h"
 #include "../dialogs/dsmessagebox.h"
+#include "../dsvdef.h"
 
 using namespace boost;
 using namespace std;
@@ -44,7 +45,13 @@ const QString Calibration::VCOMB = QT_TR_NOOP(" VCOMB");
 
 Calibration::Calibration(QWidget *parent) :
     DSDialog(parent)
-{
+{ 
+    _save_btn = NULL;
+    _abort_btn = NULL;
+    _reset_btn = NULL;
+    _exit_btn = NULL;
+    _flayout = NULL;
+
 #ifdef Q_OS_DARWIN
     Qt::WindowFlags flags = windowFlags();
     this->setWindowFlags(flags | Qt::Tool);
@@ -89,6 +96,14 @@ Calibration::Calibration(QWidget *parent) :
     retranslateUi();
 }
 
+Calibration::~Calibration(){ 
+    DESTROY_QT_OBJECT(_save_btn);
+    DESTROY_QT_OBJECT(_abort_btn);
+    DESTROY_QT_OBJECT(_reset_btn);
+    DESTROY_QT_OBJECT(_exit_btn);
+    DESTROY_QT_OBJECT(_flayout);
+}
+
 void Calibration::changeEvent(QEvent *event)
 {
     if (event->type() == QEvent::LanguageChange)
diff --git a/DSView/pv/dialogs/calibration.h b/DSView/pv/dialogs/calibration.h
index 97bf7ce2..8418606e 100755
--- a/DSView/pv/dialogs/calibration.h
+++ b/DSView/pv/dialogs/calibration.h
@@ -50,6 +50,7 @@ private:
 
 public:
     Calibration(QWidget *parent);
+    ~Calibration();
 
     void set_device(boost::shared_ptr<pv::device::DevInst> dev_inst);
 protected:
@@ -69,8 +70,7 @@ private slots:
 
 private:
     boost::shared_ptr<pv::device::DevInst>  _dev_inst;
-
-    toolbars::TitleBar *_titlebar;
+ 
     QPushButton *_save_btn;
     QPushButton *_abort_btn;
     QPushButton *_reset_btn;
diff --git a/DSView/pv/dialogs/deviceoptions.cpp b/DSView/pv/dialogs/deviceoptions.cpp
index 3ac73ad2..fe8513ed 100755
--- a/DSView/pv/dialogs/deviceoptions.cpp
+++ b/DSView/pv/dialogs/deviceoptions.cpp
@@ -30,10 +30,11 @@
 
 #include "dsmessagebox.h"
 #include <pv/prop/property.h>
+#include "../dsvdef.h"
 
 using namespace boost;
 using namespace std;
-
+ 
 namespace pv {
 namespace dialogs {
 
@@ -43,6 +44,11 @@ DeviceOptions::DeviceOptions(QWidget *parent, boost::shared_ptr<pv::device::DevI
     _button_box(QDialogButtonBox::Ok, Qt::Horizontal, this),
     _device_options_binding(_dev_inst->dev_inst())
 {
+     _dynamic_box = NULL;
+     _props_box = NULL;
+     _config_button = NULL;
+     _cali_button = NULL;
+
     _props_box = new QGroupBox(tr("Mode"), this);
     _props_box->setLayout(get_property_form(_props_box));
     _layout.addWidget(_props_box);
@@ -73,6 +79,13 @@ DeviceOptions::DeviceOptions(QWidget *parent, boost::shared_ptr<pv::device::DevI
     _mode_check.start();
 }
 
+DeviceOptions::~DeviceOptions(){
+    DESTROY_QT_OBJECT(_dynamic_box);
+    DESTROY_QT_OBJECT(_props_box);
+    DESTROY_QT_OBJECT(_config_button);
+    DESTROY_QT_OBJECT(_cali_button);
+}
+
 void DeviceOptions::accept()
 {
 	using namespace Qt;
diff --git a/DSView/pv/dialogs/deviceoptions.h b/DSView/pv/dialogs/deviceoptions.h
index 0b9591f7..ae803c8a 100755
--- a/DSView/pv/dialogs/deviceoptions.h
+++ b/DSView/pv/dialogs/deviceoptions.h
@@ -57,6 +57,8 @@ class DeviceOptions : public DSDialog
 public:
     DeviceOptions(QWidget *parent, boost::shared_ptr<pv::device::DevInst> dev_inst);
 
+    ~DeviceOptions();
+
 protected:
 	void accept();
     void reject();
@@ -84,8 +86,7 @@ private slots:
 
 private:
     boost::shared_ptr<pv::device::DevInst>  _dev_inst;
-	QVBoxLayout _layout;
-    toolbars::TitleBar *_titlebar;
+	QVBoxLayout _layout; 
 
     QGroupBox *_dynamic_box;
     QGridLayout _dynamic_layout;
diff --git a/DSView/pv/dialogs/dsdialog.cpp b/DSView/pv/dialogs/dsdialog.cpp
index 81165b3f..1d8f15ff 100755
--- a/DSView/pv/dialogs/dsdialog.cpp
+++ b/DSView/pv/dialogs/dsdialog.cpp
@@ -59,6 +59,7 @@ DSDialog::DSDialog(QWidget *parent, bool hasClose, bool bBaseButton) :
     _base_button = NULL;
 
     m_callback = NULL; 
+    _clickYes = false;
     
     setWindowFlags(Qt::Dialog | Qt::FramelessWindowHint | Qt::WindowSystemMenuHint);
     setAttribute(Qt::WA_TranslucentBackground);
@@ -80,19 +81,23 @@ void DSDialog::accept()
 {
     using namespace Qt;
 
+    _clickYes = true;
     if (m_callback){
         m_callback->OnDlgResult(true);
     }
 
+
     QDialog::accept();
 }
 
 void DSDialog::reject()
 {
     using namespace Qt;
+    _clickYes = false;
+
     if (m_callback){
         m_callback->OnDlgResult(false);
-    }
+    } 
 
     QDialog::reject();
 }
@@ -114,7 +119,8 @@ int DSDialog::exec()
       //ok,cancel
     if (m_bBaseButton){
         _base_button = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel,Qt::Horizontal, this);
-        _main_layout->addWidget(_base_button);//, 5, 1, 1, 1, Qt::AlignHCenter | Qt::AlignBottom);
+         _main_layout->addWidget(_base_button);//, 5, 1, 1, 1, Qt::AlignHCenter | Qt::AlignBottom);
+        //_main_layout->addWidget(_base_button,0, Qt::AlignHCenter | Qt::AlignBottom);
         connect(_base_button, SIGNAL(rejected()), this, SLOT(reject()));
         connect(_base_button, SIGNAL(accepted()), this, SLOT(accept()));
     }
@@ -142,6 +148,9 @@ void DSDialog::build_base(bool hasClose)
     _main_layout->addWidget(_titlebar);  
     _base_layout->addWidget(_main_widget);
     setLayout(_base_layout);  
+
+    _main_layout->setAlignment(Qt::AlignCenter | Qt::AlignTop);
+  
 } 
 
 } // namespace dialogs
diff --git a/DSView/pv/dialogs/dsdialog.h b/DSView/pv/dialogs/dsdialog.h
index 22799aa2..00f83ef7 100755
--- a/DSView/pv/dialogs/dsdialog.h
+++ b/DSView/pv/dialogs/dsdialog.h
@@ -56,6 +56,7 @@ public:
     void setTitle(QString title);
     void reload(); 
     int exec();
+    inline bool IsClickYes(){return _clickYes;}
 
 protected:
     void accept();
@@ -74,6 +75,7 @@ private:
    
     QPoint              _startPos; 
     bool                 m_bBaseButton; 
+    bool                _clickYes;
 
     IDlgCallback        *m_callback;
 };
diff --git a/DSView/pv/dialogs/dsomeasure.cpp b/DSView/pv/dialogs/dsomeasure.cpp
index d1acaa19..a454d86c 100755
--- a/DSView/pv/dialogs/dsomeasure.cpp
+++ b/DSView/pv/dialogs/dsomeasure.cpp
@@ -31,6 +31,7 @@
 #include <QBitmap>
 
 #include <boost/foreach.hpp>
+#include "../dsvdef.h"
 
 using namespace boost;
 using namespace std;
@@ -48,6 +49,8 @@ DsoMeasure::DsoMeasure(SigSession &session, View &parent,
     _button_box(QDialogButtonBox::Reset | QDialogButtonBox::Cancel,
         Qt::Horizontal, this)
 {
+    _measure_tab = NULL;
+
     setMinimumSize(500, 400);
 
     _measure_tab = new QTabWidget(this);
@@ -79,6 +82,10 @@ DsoMeasure::DsoMeasure(SigSession &session, View &parent,
     connect(_session.get_device().get(), SIGNAL(device_updated()), this, SLOT(reject()));
 }
 
+DsoMeasure::~DsoMeasure(){
+    DESTROY_QT_OBJECT(_measure_tab);
+}
+
 void DsoMeasure::add_measure(QWidget *widget, const boost::shared_ptr<view::DsoSignal> dsoSig)
 {
     const int Column = 5;
@@ -86,6 +93,7 @@ void DsoMeasure::add_measure(QWidget *widget, const boost::shared_ptr<view::DsoS
     QGridLayout *layout = new QGridLayout(widget);
     layout->setMargin(0);
     layout->setSpacing(0);
+    
     for (int i=DSO_MS_BEGIN+1; i<DSO_MS_END; i++) {
         QToolButton *button = new QToolButton(this);
         button->setProperty("id", QVariant(i));
diff --git a/DSView/pv/dialogs/dsomeasure.h b/DSView/pv/dialogs/dsomeasure.h
index ab9c25ea..5016fda7 100755
--- a/DSView/pv/dialogs/dsomeasure.h
+++ b/DSView/pv/dialogs/dsomeasure.h
@@ -49,8 +49,9 @@ class DsoMeasure : public DSDialog
 	Q_OBJECT
 
 public:
-    DsoMeasure(SigSession &session, view::View &parent,
-               unsigned int position, int last_sig_index);
+    DsoMeasure(SigSession &session, view::View &parent, unsigned int position, int last_sig_index);
+
+    ~DsoMeasure();
 
     static QString get_ms_icon(int ms_type);
     static QString get_ms_text(int ms_type);
@@ -70,12 +71,10 @@ private:
     SigSession &_session;
     view::View &_view;
     unsigned int _position;
-
-    toolbars::TitleBar *_titlebar;
+ 
     QDialogButtonBox _button_box;
     QTabWidget *_measure_tab;
-    QVBoxLayout _layout;
-    std::vector<QToolButton *> _mbtn_vec;
+    QVBoxLayout _layout; 
 };
 
 } // namespace dialogs
diff --git a/DSView/pv/dialogs/fftoptions.cpp b/DSView/pv/dialogs/fftoptions.cpp
index 3436ff7f..9202500d 100755
--- a/DSView/pv/dialogs/fftoptions.cpp
+++ b/DSView/pv/dialogs/fftoptions.cpp
@@ -34,7 +34,7 @@
 
 using namespace boost;
 using namespace std;
-
+ 
 namespace pv {
 namespace dialogs {
 
@@ -44,6 +44,18 @@ FftOptions::FftOptions(QWidget *parent, SigSession &session) :
     _button_box(QDialogButtonBox::Ok | QDialogButtonBox::Cancel,
         Qt::Horizontal, this)
 {
+    _len_combobox = NULL;
+    _interval_combobox = NULL;
+    _en_checkbox = NULL;
+    _ch_combobox = NULL;
+    _window_combobox = NULL;
+    _dc_checkbox = NULL;
+    _view_combobox = NULL;
+    _dbv_combobox = NULL;
+    _hint_label = NULL;
+    _glayout = NULL;
+    _layout = NULL;
+
     _en_checkbox = new QCheckBox(this);
     _len_combobox = new QComboBox(this);
     _interval_combobox = new QComboBox(this);
@@ -173,7 +185,7 @@ FftOptions::FftOptions(QWidget *parent, SigSession &session) :
     QPixmap pixmap(hint_pic);
     _hint_label->setPixmap(pixmap);
 
-    _glayout = new QGridLayout();
+    _glayout = new QGridLayout();  //QGridLayout
     _glayout->setVerticalSpacing(5);
     _glayout->addWidget(new QLabel(tr("FFT Enable: "), this), 0, 0);
     _glayout->addWidget(_en_checkbox, 0, 1);
@@ -208,6 +220,10 @@ FftOptions::FftOptions(QWidget *parent, SigSession &session) :
     connect(_session.get_device().get(), SIGNAL(device_updated()), this, SLOT(reject()));
 }
 
+FftOptions::~FftOptions(){
+
+}
+
 void FftOptions::accept()
 {
     using namespace Qt;
diff --git a/DSView/pv/dialogs/fftoptions.h b/DSView/pv/dialogs/fftoptions.h
index b16dfe60..2486c871 100755
--- a/DSView/pv/dialogs/fftoptions.h
+++ b/DSView/pv/dialogs/fftoptions.h
@@ -52,6 +52,8 @@ private:
 public:
     FftOptions(QWidget *parent, SigSession &session);
 
+    ~FftOptions();
+
 protected:
     void accept();
     void reject();
@@ -63,8 +65,7 @@ private slots:
 private:
     SigSession &_session;
     uint64_t _sample_limit;
-
-    toolbars::TitleBar *_titlebar;
+ 
     QComboBox *_len_combobox;
     QComboBox *_interval_combobox;
     QCheckBox *_en_checkbox;
diff --git a/DSView/pv/dialogs/interval.cpp b/DSView/pv/dialogs/interval.cpp
index e2ff752b..7ab456b7 100755
--- a/DSView/pv/dialogs/interval.cpp
+++ b/DSView/pv/dialogs/interval.cpp
@@ -32,6 +32,11 @@ Interval::Interval(SigSession &session, QWidget *parent) :
     _button_box(QDialogButtonBox::Ok,
         Qt::Horizontal, this)
 {
+    _interval_label = NULL;
+    _interval_spinBox = NULL;
+    _interval_slider = NULL;
+
+
     setMinimumWidth(300);
     _interval_label = new QLabel(tr("Interval(s): "), this);
     _interval_spinBox = new QSpinBox(this);
diff --git a/DSView/pv/dialogs/lissajousoptions.cpp b/DSView/pv/dialogs/lissajousoptions.cpp
index 5f502f81..02c98167 100755
--- a/DSView/pv/dialogs/lissajousoptions.cpp
+++ b/DSView/pv/dialogs/lissajousoptions.cpp
@@ -33,6 +33,7 @@
 
 #include <boost/foreach.hpp>
 
+
 using namespace boost;
 using namespace std;
 using namespace pv::view;
@@ -46,6 +47,12 @@ LissajousOptions::LissajousOptions(SigSession &session, QWidget *parent) :
     _button_box(QDialogButtonBox::Ok | QDialogButtonBox::Cancel,
         Qt::Horizontal, this)
 {
+    _enable = NULL;
+    _x_group = NULL;
+    _y_group = NULL;
+    _percent = NULL;
+    _layout = NULL;
+
     setMinimumSize(300, 300);
 
     _enable = new QCheckBox(this);
diff --git a/DSView/pv/dialogs/lissajousoptions.h b/DSView/pv/dialogs/lissajousoptions.h
index b3fd13f1..b0653548 100755
--- a/DSView/pv/dialogs/lissajousoptions.h
+++ b/DSView/pv/dialogs/lissajousoptions.h
@@ -73,10 +73,11 @@ private:
     QGroupBox *_x_group;
     QGroupBox *_y_group;
     QSlider *_percent;
+    QGridLayout *_layout;
+
     QVector<QRadioButton *> _x_radio;
     QVector<QRadioButton *> _y_radio;
-    QDialogButtonBox _button_box;
-    QGridLayout *_layout;
+    QDialogButtonBox _button_box;  
 };
 
 } // namespace dialogs
diff --git a/DSView/pv/toolbars/trigbar.cpp b/DSView/pv/toolbars/trigbar.cpp
index d63d857b..95f336f4 100755
--- a/DSView/pv/toolbars/trigbar.cpp
+++ b/DSView/pv/toolbars/trigbar.cpp
@@ -316,9 +316,8 @@ void TrigBar::on_actionLissajous_triggered()
 }
 
  void TrigBar::on_application_param(){
-     pv::dialogs::MathOptions math_dlg(_session, this);
-    math_dlg.exec();
-    return;
+   //  pv::dialogs::MathOptions math_dlg(_session, this);  math_dlg.exec();   return;
+    
      pv::dialogs::ApplicationParamDlg dlg;
      dlg.ShowDlg(this);
  }
diff --git a/DSView/pv/view/viewport.cpp b/DSView/pv/view/viewport.cpp
index 141884c8..1bf6720f 100755
--- a/DSView/pv/view/viewport.cpp
+++ b/DSView/pv/view/viewport.cpp
@@ -37,12 +37,12 @@
 
 #include <QMouseEvent>
 #include <QStyleOption>
-#include <QPainterPath>
-
-#include <math.h>
-
+#include <QPainterPath> 
+#include <math.h> 
 #include <boost/foreach.hpp>
 
+#include "../config/appconfig.h"
+
 using namespace boost;
 using namespace std;
 
@@ -91,24 +91,20 @@ Viewport::Viewport(View &parent, View_type type) :
     // drag inertial
     _drag_strength = 0;
     _drag_timer.setSingleShot(true);
-
-    connect(&trigger_timer, SIGNAL(timeout()),
-            this, SLOT(on_trigger_timer()));
-    connect(&_drag_timer, SIGNAL(timeout()),
-            this, SLOT(on_drag_timer()));
-
-    connect(&_view.session(), &SigSession::receive_data,
-            this, &Viewport::set_receive_len);
-
+ 
     _cmenu = new QMenu(this);
     QAction *yAction = _cmenu->addAction(tr("Add Y-cursor"));
     QAction *xAction = _cmenu->addAction(tr("Add X-cursor"));
+ 
+    setContextMenuPolicy(Qt::CustomContextMenu);
+
+    connect(&trigger_timer, SIGNAL(timeout()),this, SLOT(on_trigger_timer()));
+    connect(&_drag_timer, SIGNAL(timeout()),this, SLOT(on_drag_timer()));
+    connect(&_view.session(), &SigSession::receive_data, this, &Viewport::set_receive_len);
+
     connect(yAction, SIGNAL(triggered(bool)), this, SLOT(add_cursor_y()));
     connect(xAction, SIGNAL(triggered(bool)), this, SLOT(add_cursor_x()));
-
-    setContextMenuPolicy(Qt::CustomContextMenu);
-    connect(this, SIGNAL(customContextMenuRequested(const QPoint&)),
-            this, SLOT(show_contextmenu(const QPoint&)));
+    connect(this, SIGNAL(customContextMenuRequested(const QPoint&)),this, SLOT(show_contextmenu(const QPoint&)));
 }
 
 int Viewport::get_total_height() const
@@ -757,14 +753,19 @@ void Viewport::mouseMoveEvent(QMouseEvent *event)
 void Viewport::mouseReleaseEvent(QMouseEvent *event)
 {
     assert(event);
-
-    if (_type == TIME_VIEW) {
+    
+    if (_type != TIME_VIEW){
+        update();
+        return;
+    }
+  
         if ((_action_type == NO_ACTION) &&
             (event->button() == Qt::LeftButton)) {
             if (_view.session().get_device()->dev_inst()->mode == LOGIC &&
                 _view.session().get_capture_state() == SigSession::Stopped) {
-                // priority 1
-                if (_action_type == NO_ACTION) {
+                //priority 1
+                //try to quick scroll view
+                if (_action_type == NO_ACTION && AppConfig::Instance()._appOptions.quickScroll) {
                     const double strength = _drag_strength*DragTimerInterval*1.0/_elapsed_time.elapsed();
                     if (_elapsed_time.elapsed() < 200 &&
                         abs(_drag_strength) < MinorDragOffsetUp &&
@@ -936,7 +937,7 @@ void Viewport::mouseReleaseEvent(QMouseEvent *event)
             }
             _action_type = NO_ACTION;
         }
-    }
+    
     update();
 }
 
@@ -1621,7 +1622,7 @@ void Viewport::on_trigger_timer()
 }
 
 void Viewport::on_drag_timer()
-{
+{   
     const int64_t offset = _view.offset();
     const double scale = _view.scale();
     if (_view.session().get_capture_state() == SigSession::Stopped &&